Surgical stapler with universal articulation and tissue pre-clamp

ABSTRACT

A tool assembly for a surgical stapling device includes a channel member for supporting a staple cartridge therein and an anvil to deform a plurality of staples ejected from the staple cartridge thereagainst. The tool assembly also includes a sled which is movable to force the staples from the cartridge against the anvil to staple tissue disposed between the anvil and the staple cartridge. A dynamic clamping member is included which has a pin which movably engages the anvil and a flange which movably engages the channel assembly. The dynamic clamping member is mounted to and movable with the sled. The pin and the flange of the dynamic clamping member cooperating to oppose the forces associated with clamping and stapling tissue and also to maintain a substantially uniform gap between the anvil and the staple cartridge during stapling of the tissue.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/855,166, filed Apr. 2, 2013, now U.S. Pat. No. 10,130,360, which is acontinuation of U.S. patent application Ser. No. 13/553,926, filed Jul.20, 2012, now (Abandoned), which is a continuation of U.S. patentapplication Ser. No. 11/998,035, filed Nov. 28, 2007, now (U.S. Pat. No.8,596,513), which is a continuation of U.S. patent application Ser. No.10/529,799, filed Mar. 30, 2005, now (U.S. Pat. No. 7,726,537), which isa U.S. National Stage Application filed under 35 U.S.C. § 371(a) ofInternational Patent Application Serial No. PCT/US2003/031716, filedOct. 6, 2003, which claims priority from U.S. Provisional PatentApplication Ser. No. 60/416,372, filed Oct. 4, 2002. Each of theseapplications are incorporated herein in its entirety by reference.

BACKGROUND 1. Technical Field

This application relates to a surgical stapling apparatus, and moreparticularly, to an articulating endoscopic surgical stapling apparatuswhich sequentially applies a plurality of surgical fasteners to bodytissue and subsequently incises the fastened tissue.

2. Background of Related Art

Surgical devices wherein tissue is first grasped or clamped betweenopposing jaw structure and then joined by surgical fasteners are wellknown in the art. Typically, a knife is employed after the tissue isfastened to cut the tissue along a preferred cutting path. The fastenersare typically in the form of surgical staples but other types offasteners can also be utilized to accomplish the same or similarpurpose.

Instruments for this purpose can include two elongated members which arerespectively used to capture or clamp tissue. Typically, one of themembers carries a staple cartridge which houses a plurality of staplesarranged in at least two lateral rows while the other member has ananvil that defines a surface for forming the staple legs as the staplesare driven from the staple cartridge. Generally, the stapling operationis effected by cam bars or sleds that have cam surfaces that travellongitudinally through the staple cartridge and staple pushers thatsequentially eject the staples from the staple cartridge. Typically, aknife travels between the staple rows to longitudinally cut and/or openthe stapled tissue between the rows of formed staples.

One of the issues associated with prior stapler designs is the tendencyfor the dynamic clamping member to skew or buckle as it passes throughthe tissue due to the large forces generated during stapling and cuttingtissue. For example, prior dynamic clamping member designs that carrythe knife or cutting surface provide cantilever-like designs which aredesigned to effectively squeeze tissue ahead of the knife blade and thestaple forming sled to force fluids from the tissue which enhancestissue stapling and contributes to a successful tissue staple. However,the large forces required to staple and incise tissue tend to placeundue stresses on the cantilever knife design which may cause the knifeto skew or buckle during translation often requiring the surgeon to firethe stapler very slowly through larger tissue structures to avoid thepossibility of the knife traveling off line.

It is an object of this disclosure to provide a surgical stapler havingan actuator, preferably, a dynamic clamping member which enhances tissuestapling by forcing fluids out of the clamped tissue before ejectingstapling into and stapling the tissue. Another object of this disclosureis to provide a dynamic clamp member that applies substantially clampingpressure upon the anvil and cartridge assembly of the tool member of asurgical stapler as the dynamic clamping member translates along andthrough the tool assembly.

Another object of this disclosure is to provide a dynamic clampingmember that helps to provide a uniform tissue gap between the tissuecontacting surfaces of an anvil and a staple cartridge in the immediatearea of and during sequential, progressive staple formation and tissuefastening, as well as in the area of and during tissue cutting, ifcutting is being performed.

SUMMARY

The present disclosure relates to a tool assembly for a surgicalstapler, which tool assembly includes a channel member for supporting astaple cartridge therein and an anvil for deforming a plurality ofstaples pushed from the staple cartridge thereagainst. At least one sledis included which moves from a first position out of operativeengagement with the plurality of staples or staple pushers to asubsequent positions which progressively and sequentially force thestaples from the staple cartridge through the tissue disposed in the gapbetween the anvil and the staple cartridge and against the anvil suchthat the staples deform and staple or fasten the tissue. Typically andpreferably, the sled includes at least one angled surface which uponmovement thereof engages staple pushers that force the staples from thestaple cartridge and against the anvil.

The present disclosure also includes a dynamic clamping member which ismovable with the sled and which includes a first mechanical interfacewhich engages the anvil and a substantially opposed second mechanicalinterface which engages the channel assembly. The first and secondmechanical interfaces of the dynamic clamping member are in substantialvertical registration relative to one another to oppose the forcesassociated with damping and stapling tissue and to maintain asubstantially uniform gap between the anvil and the staple cartridgeduring stapling.

Preferably, the first mechanical interface of the dynamic clampingmember includes a pin which translates within a corresponding slotdisposed within the anvil upon movement of the clamp assembly. Thesecond mechanical interface of the dynamic damping member preferablyincludes a central support or upward extension which translates within acorresponding slot disposed within the channel assembly upon movement ofthe dynamic clamping member. Advantageously, the pin and the flange aredimensioned to oppose the forces associated with the sled forcing theplurality of staples against the anvil to staple tissue disposedtherebetween.

In one embodiment, the tool assembly includes a selectively movableclamping collar which biases against a cam surface on the anvil to closethe anvil relative to the staple cartridge and grasp tissuetherebetween.

Another embodiment according to the present disclosure relates to anarticulating assembly for a surgical stapling device which includes anelongated shaft having proximal and distal ends and a longitudinal “X”axis defined therethrough. The shaft is selectively rotatable about thelongitudinal “X” axis. The articulating assembly also includes a toolassembly which attaches to the distal end of the shaft and includes atube adapter which pivotably mounts a pivot block to allow pivotablemovement of the tool assembly about a “Y” axis defined perpendicular tothe “X” axis and a “Z” axis define perpendicular to the “X” axis.

Preferably, the tool assembly also includes an anvil having a bottomsurface and a channel assembly to support a staple cartridge therein.The staple cartridge includes a plurality of staples therein and atissue contacting upper surface which opposes the bottom surface of theanvil. A movable sled is also included which has at least one angledsurface which is designed to force the plurality of staples to deformagainst the bottom surface of the anvil. The tool assembly also includesa dynamic clamping member which moves with the sled to sever tissueafter deformation of the staples against the anvil. Preferably, rotationof the shaft about the longitudinal “X” axis correspondingly rotates thetool assembly about the longitudinal “X” axis.

In another embodiment, the tool assembly includes a selectively movableclamping collar which biases against a cam surface on the anvil to closethe anvil relative to the staple cartridge to grasp tissue therebetween.

In another embodiment, the dynamic damping member includes a firstmechanical interface which translates within a corresponding slotdisposed within the anvil upon movement of the sled and a secondmechanical interface which translates within a corresponding slotdisposed within the channel assembly upon movement of the sled.Preferably, the first mechanical interface includes a pin and the secondmechanical interface includes a flange or plate. Advantageously, the pinand the flange or plate are dimensioned and/or positioned to oppose theforces associated with deforming the plurality of staples against theanvil to staple tissue disposed therebetween. These forces include thoseassociated with the resistance of compression of the tissue, andsqueezing and movement or flow of fluid within the tissue.

The present disclosure also relates to a tool assembly for a surgicalstapling device which includes an anvil having a longitudinally disposedslot defined therethrough and a channel assembly which also has alongitudinally disposed slot also defined therethrough. A staplecartridge having a plurality of staples disposed therein mechanicallymounts to the channel assembly. A sled is included preferably as part ofthe tool assembly and which is selectively movable along the staplecartridge to force the plurality of staples to deform against a bottomsurface of the anvil. The dynamic clamping assembly can include a bottomcamming surface or member, e.g., a flange, and an upwardly extendingsupport or extension which extends upwardly from the bottom flange.

Preferably, the upwardly extending support or extension includes aleading cutting edge for severing tissue and an aperture defined throughthe dynamic clamping member for receiving a pin therein. The pin isadvantageously configured to ride along the slot defined within theanvil and the bottom flange is advantageously configured to mountthrough the sled and into the slot defined within the channel assembly.Movement of the sled moves the dynamic clamping member not only tostaple tissue through the staple cartridge but preferably also to severtissue after stapling it.

The pin and the bottom flange of the dynamic clamping member are betterpositioned to cooperatively oppose the forces associated with clampingand stapling tissue and maintain a substantially uniform gap between theanvil and the staple cartridge during progressive stapling as thedynamic clamping member translates along the tool assembly. Preferably,the tool assembly includes a selectively movable clamping collar whichbiases against a cam surface on a proximal portion of the anvil to closeor pre-clamp the anvil relative to the staple cartridge to grasp tissuetherebetween.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the subject instrument are described herein withreference to the drawings wherein:

FIG. 1A is a perspective view of a surgical stapler for use with a toolassembly according to the present disclosure;

FIG. 1B is a perspective view of the tool assembly of the surgicalstapler according to the present disclosure;

FIG. 2 is an exploded view of the tool assembly of FIG. 1;

FIG. 3 is a right, perspective cross section of the tool assembly ofFIG. 1 showing internal components thereof;

FIG. 4 is a left, side, partial cross sectional view showing a dynamicclamping member according to the present disclosure;

FIG. 5 is a top, perspective view showing an anvil for forming a seriesof surgical fasteners according to the present disclosure;

FIG. 6A is a side, perspective view of a channel assembly for supportinga staple cartridge according to the present disclosure;

FIG. 6B is a top, perspective view of the channel assembly of FIG. 6A;

FIG. 7A is a side, perspective view of a sled for supporting the dynamicclamping member according to the present disclosure;

FIG. 7B is a top, perspective view of the sled of FIG. 7A;

FIG. 7C is a perspective view showing the dynamic clamping memberdisposed within the sled;

FIG. 8 is a side, perspective view of a pivot block which mounts thetool assembly to a shaft of the surgical stapler to permit articulationof the tool assembly relative to the shaft;

FIG. 9 is a side, perspective view of an adapter for mounting the pivotblock to the shaft of the surgical stapler;

FIG. 10 is a side, perspective view of the dynamic clamping memberaccording to the present disclosure;

FIG. 11A is a front perspective view of a distal end of a staplecartridge for use in accordance with the present disclosure;

FIG. 11B is a side, cross sectional view of the tool assembly shown in;

FIG. 1B and the cartridge assembly shown in FIG. 11A;

FIG. 11C is a bottom perspective view with parts separated of thecartridge assembly of FIG. 11A;

FIG. 11D shows an enlarged view of the cooperative relationship betweenthe sled, the surgical fasteners and a plurality of staple pushers whichform part of the staple cartridge of FIGS. 11A-11C;

FIG. 12A is a schematic illustration of a pulley-like drive system foradvancing the sled through the tissue, including a pair of belts;

FIG. 12B is a schematic illustration of a pulley-like drive system foradvancing the sled through the tissue, including a single belt;

FIG. 13 is a side cross sectional schematic view showing one possibleactuating mechanism for actuating a clamp to compress and cut tissue;

FIG. 14 is a perspective view of an alternate dynamic clamping memberdesign according to the present disclosure.

DETAILED DESCRIPTION

FIG. 1A shows a surgical stapler, generally designated 1, for use invarious open, endoscopic or laparoscopic surgical procedures. Stapler 1includes a housing 3 having distal and proximal ends 4 and 6,respectively, an elongated shaft 20 mounted to housing 3, preferably toits distal end 4, and a handle assembly generally designated 5. Shaft 20has a distal end 20 a to which is operatively attached by attachmentmechanism 20 b to a disposable loading unit 10. As also shown in FIG.1B, disposable loading unit (DLU) 10 is comprised of a tool assembly 100and a shaft connector portion 20 c which are pivotally and operativelyattached to each other through connector mechanism C. Shaft connectorportion 20 c is removably operatively attached to proximal end 24 ofdistal end 20 a of shaft 20.

It is within the scope of this disclosure that tool assembly 100 may bepivotally, operatively, integrally attached, for example, through aconnection mechanism such as C permanently and directly to distal end 20a of shaft 20 of a disposable surgical stapler. As is known, a used orspent disposable loading unit 10 can be removed from shaft 20 of areusable or reposable open, endoscopic or laparoscopic surgical stapler,and replaced with an unused disposable unit. It is contemplated thatshaft 20 with or without an integral or removably attached disposableloading unit can be selectively removable from housing 3.

Shaft connector portion 20 includes a proximal end 24 and a distal end22. As mentioned above, the proximal end 24 is can be permanently orremovably associated with a handle or other actuating assemblies of amanually (or other, e.g., robotic or computer) operated open orendoscopic surgical stapler 1 (or system—not shown). Distal end 22 ofshaft connector portion 20 is operatively connected to tool assembly100. Tool assembly 100, in general, includes a cartridge channelassembly 120, an anvil assembly 110 and a staple cartridge assembly 200.Tool assembly 100 also includes an actuator, preferably a dynamicclamping member 150, a sled 160, as well as staple pushers 228 andstaples 350 once an unspent or unused cartridge 200 is in or mounted inchannel assembly 120.

In the drawings and in the descriptions which follow, the term“proximal”, as is traditional, will refer for example to the end of toolassembly 100 which is closer to the user, while the term “distal” willrefer to the end which is further from the user.

Shaft connector portion 20 c is preferably cylindrical and defines aninternal channel 25 at the distal end 22 thereof and which isdimensioned to receive a tube adapter or adapter 40 which will bedescribed in more detail with respect to FIG. 9 below. Shaft connectorportion 20 c also receives or houses actuators for actuating toolassembly 100. As best shown in FIGS. 1A, 1B, 2 and 9, tool assembly 100mounts to distal end 22 of shaft connector 20 c (or the distal end 20 aof shaft 20). Commonly owned U.S. application Ser. No. 60/479,379includes one possible design of a stapler with a tool assembly mountedthereto, the entire contents of this application being incorporated byreference herein.

More particularly, tool assembly 100 is mounted onto tube adapter 40which includes an outer cylindrical surface 47 that is slidinglyreceived in friction-fit engagement and attached to internal housing 25of shaft connector 20 c (or, again, to shaft 20). Herein, thedescription of the proximal connection or attachment of tool assembly100 to shaft connector 20 c also applies to its connection to shaft 20.Preferably, the outer surface 47 of the tube adapter 40 includes atleast one mechanical interface, e.g., a cutout or notch 45, which mateswith a corresponding mechanical interface, e.g., a radially inwardlyextending protrusion or detent (not shown), disposed on the innerperiphery of internal housing 25 to lock the tube adapter 40 to theshaft connector 20 c. As a result, rotation of shaft 20 about an “X”axis defined with respect to tool assembly 100 (See FIG. 3)correspondingly rotates tool assembly 100 in the same direction.

As best shown in FIGS. 1B, 3, 4, 8 and 9, the distal end of tube adapter40 includes a pair of opposing flanges 42 a and 42 b which define acavity 41 for pivotably receiving a pivot block 50 therein. Moreparticularly, each flange 42 a and 42 b includes an aperture 44 a and 44b (FIG. 8) defined therein which receives pivot pin 57 (FIG. 4) alsoreceived in apertures 52 a, 52 b of pivot block 50 to allow pivotablemovement of pivot block 50 about a “Z” axis defined as perpendicular tolongitudinal axis “X” of tool assembly 100 (See FIGS. 3 and 8).

As explained in more detail below in the description of the channelassembly 120, the proximal end of each upwardly extending flange 121 aand 121 b of the channel assembly 120 includes a pair of apertures 122 aand 122 b disposed therethrough which are dimensioned to receive a pivotpin 59 (FIG. 6A). In turn, pivot pin 59 mounts through apertures 53 a,53 b of pivot block 50 to permit rotation of the tool assembly 100 aboutthe “Y” axis as needed during a given surgical procedure (FIGS. 3 and8).

An actuator or a plurality of actuators (not shown) preferably passthrough shaft connector portion 20 c, tube adapter 40 and pivot block 50and operably connect to tool assembly 100 to permit the surgeon toarticulate tool assembly 100 about the “Y” and “Z” axes as needed duringa surgical procedure. In addition, shaft 20 of surgical stapler 1 isrotatable 3600 by the rotation of knob “K”. As a result, tool assembly100 is articulatable at least 90 degrees in all directions. Variousactuators, hand assemblies and pivot blocks are envisioned which can beutilized to accomplish this task some of which are identified incommonly-owned U.S. Pat. Nos. 6,250,532 and 6,330,965 and U.S.Provisional Application Ser. No. 60/479,379 filed on Jun. 17, 2003entitled “Surgical Stapling Device, the entire contents of all of whichare hereby incorporated by reference herein.

As best seen in FIGS. 1B and 2 and as mentioned above, tool assembly 100includes anvil assembly 110 and channel assembly 120. Channel assembly120 supports staple cartridge assembly 200, an actuator, e.g., a dynamicclamping member 150, and a sled 160. As such, these various assembliesand their respective internal components, when assembled, cooperate toallow the tool assembly to manipulate, grasp, clamp, fasten and,preferably, sever tissue 400 during a given surgical procedure asexplained below.

Generally, the top and bottom halves of a portion of tool assembly 100are defined by anvil assembly 110 and cartridge channel assembly 120.Staple cartridge assembly 200 mounts within channel assembly 120 andincludes an upper tissue contacting or facing surface 231 which opposesa tissue contacting or facing bottom anvil surface 114 b of anvilassembly 110. As best seen in FIG. 1B, anvil assembly 110 and channelassembly 120 (and, thus, when mounted, staple cartridge assembly 200)are pivotably coupled near the proximal end of tool assembly 100 toallow anvil assembly 110 to pivot with respect to channel assembly 120(and staple cartridge assembly 200). More particularly, anvil assembly110 and channel assembly 120 are pivotably coupled with respect to oneanother by two mechanical elements, namely, upwardly extending flanges121 a and 121 b of channel assembly 120 and pre-clamping collar 140.

More particularly, the proximal end of each sidewall or upwardlyextending flange 121 a and 121 b of channel assembly 120 includes a cutout, e.g., cul de sac 123 a, 123 b, which are configured to pivotablyreceive a pair of corresponding protrusions or detents 119 a (not shown)and 119 b which extend laterally from the proximal end of the anvilassembly 110. This allows the anvil assembly 110 to pivot with respectto the channel assembly 120.

Pre-clamping collar 140 is designed to encompass and clamp or preferablypre-clamp the channel assembly 120 and the anvil assembly 110 togetherin an approximated and clamp position prior to tissue fastening. As canbe appreciated, by moving pre-clamping collar 140 distally the user canactuate/move the anvil assembly 110 from an open, first position towardchannel assembly 120 to approximate the jaws, i.e., the anvil 110 andcartridge 200, to a second, closed position to grasp tissue 400therebetween. The sled 160 can be actuated by the user to staple andsubsequently incise the tissue 400. The details of sled 160, dynamicclamping member 150 and the staple cartridge assembly 200 are describedin further detail below. Pre-clamp is understood to mean that dampingcollar 140 approximates and damps the anvil and cartridge assembliesfrom or at the proximal end portions before stapling and before dynamicdamping member 150 (or 150″) subsequently progressively clamps the anviland cartridge assemblies in the area of stapling and preferably cuttingtissue as the dynamic damping member translates through the toolassembly 100.

As best seen in FIGS. 7A, 7C, 11B and 11D, sled 160 includes a pair ofupwardly-extending cam wedges 161 a and 161 b (See FIG. 7A) which, whenactuated to move by the user, cam a series of surgical fasteners 500 orstaples (See FIG. 11D) into and through the tissue 400 (FIG. 11B) andagainst staple forming pockets 111 of anvil assembly 110 to deform thefasteners 350 and fasten tissue 400 therewith. Dynamic damping member150 is associated with, e.g., mounted on and rides on, or with or isconnected to or integral with and/or rides behind sled 160. It isenvisioned that dynamic damping member 150 can have cam wedges or camsurfaces attached or integrally formed or be pushed by a leading distalsurface thereof.

As shown, dynamic clamping member 150 is disposed or seated in sled 160behind upwardly-extending wedges 161 a and 161 b such after the surgicalfasteners 500 are fired and formed against anvil bottom surface 114 b,the dynamic clamping member 150 severs tissue 400 between the two rowsof fasteners 500. Details of the various above-mentioned subassembliesand components of the tool assembly 100 and the inter-cooperatingfeatures among all the same are described in more detail below withrespect to the corresponding figure drawings.

As shown in FIGS. 1B, 2, 4, 5, 6A and 11B, anvil assembly 110 preferablyis elongated and includes a proximal end 116, a distal end 118 and topand bottom surfaces 114 a and 114 b, respectively. As explained above, apair of rocker pins 119 a (not shown) and 119 b are disposed nearproximal end 116 and are designed for pivotable engagement withcorresponding pair of cutouts 123 a and 123 b defined within thesidewalls 121 a, 121 b near the proximal end of the channel assembly120. It is contemplated that actuation by conventional means (e.g.,activated remotely; e.g., by a handle assembly 5 (FIG. 1A)) will causeclamping collar 140 to move in a distal direction and engage forward camsurface 115 of anvil assembly 110. This will cause the anvil assembly110 to pivot from an open first position wherein the anvil assembly 110and the channel assembly 120 are disposed in spaced relation relative toone another to a second closed position wherein anvil assembly 110 andstaple cartridge assembly 120 cooperate to grasp tissue 400therebetween, i.e., pre-clamp the tissue between tissue engaging surface114 b of anvil and opposing tissue engaging surface 231 of staplecartridge assembly 200.

More particularly, it is envisioned that the initial grasping orpre-clamping of tissue essentially squeezes or forces fluids laterallyand axially from the tissue 400 thus reducing the likelihood of thestaples being hydraulically displaced during staple deformation.Movement of clamping collar 140 proximally over proximal cam surface 117will pivot anvil assembly 110 about pins 119 a, 119 b to open the anvilassembly 110 relative to the staple cartridge assembly 200. Inaccordance with this disclosure the grasping, i.e., clamping of tissueby clamping collar 140 is referred to as pre-clamping the tissue, i.e.,before the dynamic clamping member subsequently clamps, preferably,further damps or compresses, tissue.

Preferably, anvil assembly 110 is made from a suitable heavy gaugematerial such as, e.g., 301 surgical stainless steel (or otherhigh-strength and durable material) to resist the forces of stapleejection and formation against the anvil bottom surface 114 b andespecially at the distal end portion of the anvil assembly 110, and toresist the forces associated with tissue expansion an/or fluid flowwithin the tissue during pre-clamping damping collar 140 andsubsequently damping by dynamic damping member 150, 150″ as well asduring the fastening and cutting processes. The use of the heavy gaugematerial for the anvil assembly 110 allows aperture 154 and camming pin159 of the presently disclosed dynamic clamping member 150 to beadvantageously positioned in substantial vertical registration withbottom flange 152 of damping assembly 150.

As shown in FIG. 14, the heavy gauge material of the anvil assembly 110allows an improved different dynamic damping member 150″ (or dynamicdamping member 150 of FIG. 10) to be utilized. The design of dynamicdamping member 150″ greatly reduces any tendency of the clampingassembly 150 buckling due to opposing compressive and tensile forcessince as shown in FIG. 14, there is only tensile stress along line “S”due to the bottom flange 152″ and the upper camming pin 159 (See FIG.10) in aperture 154″ being disposed in substantial vertical registrationrelative to one another.

As a result and as best illustrated by FIGS. 4 and 11B, during distaltranslation of the dynamic damping member 150 or 150″ through tissue400, the combination of the heavy gauge material of the anvil assembly110 and the substantially vertical alignment of the flange 152, knifeedge 155 and camming pin 159 disposed in aperture 154 operate to furtherproximate (i.e., further clamp) the opposing tissue engaging surfaces(i.e., anvil bottom surface 114 b and upper facing surface 231 of staplecartridge assembly 200) at a moving point which is distal to the leadingedge 155 of the knife 155 a. The further damping of the tissue distallyrelative to the translating dynamic clamping member 150 acts to maintaina maximum acceptable gap between the opposing surface 114 b and 231 andforces fluid from the tissue 400 which enhances stapling and reduces thelikelihood of hydraulically displacing the staples 500 duringdeformation.

It is also envisioned that utilization of a heavy gauge material forboth anvil assembly 110 and pre-clamping collar 140 will also provide anenhanced clamping pressure along the length of tissue 400 and help toprovide a uniform gap between the respective approximated anvil assembly110 and cartridge 200 prior to firing the stapler and translating thesled 160 and dynamic damping member 150 through the tissue 400.Moreover, utilizing pre-clamping collar 140 to pre-damp tissue 400 priorto deformation of the staples 500, also tends to force some tissue fluiddistally and axially outwardly which again reduces the likelihood ofhydraulically displacing staples 500 during deformation to fasten tissue400.

After tissue 400 is fastened and severed (as explained in more detailbelow with respect to the operation of the dynamic clamping member 150),the operator can release pre-clamping collar 140 through re-activationor reverse activation of the damping actuator (not shown). As explainedabove, the operator actuates the clamping actuator to move thepre-damping collar 140 proximally against rear cam surface 117 which, inturn, forces anvil assembly 110 to pivot to an open position aboutrocker pins 119 a and 119 b.

As best shown in FIG. 5, anvil assembly 110 includes an elongated crossor T-shaped channel or slot generally designated 112 having a dependingcentral portion or leg 112 a and a transverse upper portion 112 b. Slot112 preferably extends longitudinally from proximal end 113 of upperportion 114 a of the anvil assembly 110 to the distal end 118 thereof.Leg 112 a starts from or enters proximate end 113 of anvil assembly 110and extends to distal end 118 and upper transverse portion 112 b startsproximate cam 115 and extends to distal end 118. Preferably, upperportion 112 b is dimensioned to slidingly receive transverse pin 159that extends within aperture 154 in upper portion 157 of central supportor extension 157 of dynamic damping member 150 (see FIG. 10). Pin 159 isdimensioned to slidingly lock the upper portion 157 of dynamic clampingmember 150 within the T-shaped channel 112 such that the dynamicclamping member 150 is longitudinally-recipricable within slot 112.

As mentioned above, the pin 159 and channel 112 arrangement of thedynamic damping member 150 in the anvil assembly 110 and the arrangementof the bottom flange through slot 126 in channel assembly 120 (FIG. 6B)assures that dynamic damping member 150 and its knife blade travelbetween the surgical fasteners 500 along an ideal transverse andvertical cutting plane through the tissue 400. That is, the pin 159—slot112 and flange 152—slot 126 arrangements prevent the dynamic dampingmember 150 from skewing, i.e., laterally displacing the anvil assembly110 relative to staple cartridge assembly 200 (either vertically (“Z”axis”) or transversely (“Y” axis)) during the fastening and severingprocesses. Moreover and as explained above, these arrangements alsocounteract the clamping forces associated with compression of tissue inthe gap between anvil assembly 110 and cartridge assembly 120 and theejection and deformation of the staples 500 to keep the anvil assembly110 and the staple cartridge assembly 200 in substantially uniform andclose relation relative to one another during the progressive,sequential deformation of staples 500 and incision of the tissue 400 asdynamic clamping member 150 moves from the proximal to distal ends ofthe anvil assembly 110, channel assembly 120 or cartridge assembly 200.

As best shown in FIGS. 6A, 6B, 11A and 11B, channel assembly 120 isdimensioned to house staple cartridge assembly 200 therein. Moreparticularly, channel assembly 120 includes a bottom surface 128 havingupwardly extending side walls or flanges 121 a and 121 b which defineelongated support channel 125 which, in turn, is dimensioned tomountingly receive staple cartridge assembly 200 therein. Channelassembly 120 also includes a plurality of mechanical interfaces, hereapertures 127 a, 127 b, 127 c and 127 d, which matingly receive acorresponding plurality of mechanical interfaces, here, protrusions 235a, 235 b, 235 c and 235 d, disposed in the outer-facing surfaces ofstaple cartridge assembly 200 (FIGS. 2 and 11C).

Staple cartridge assembly 200 can be assembled and mounted withinchannel assembly 120 during the manufacturing or assembly process andsold as part of overall tool assembly 100, or staple cartridge assembly200 may be designed for selective mounting to channel assembly 120 asneeded and sold separately, e.g., as a single use replacement,replaceable or disposable staple cartridge assembly 200. Preferably,staple cartridge assembly 200 is manufactured to include sled 160 anddynamic clamping member 150. Alternatively and as discussed below withrespect to FIG. 15, dynamic clamping member 150 with a knife may be soldas part of the replaceable staple cartridge assembly 200 without a knifeblade 155 a (but preferably with a knife blade 155 a to enhance and/orinsure accurate cutting of tissue 400 after staple deformation. Toolassembly 100 may also be sold as a kit that includes a variety of staplecartridges 200 containing surgical fasteners 500 of different sizes,and/or arranged to be ejected in different patterns, any of which may beselectively-coupled to the channel assembly 120 as desired for useduring a particular operation.

The proximal end of each upwardly extending flange 121 a and 121 b ofthe channel assembly 120 includes the aforementioned cul de sacs 123 a,123 b which allow pins 119 a and 119 b of anvil assembly 110 to pivottherein, and apertures 122 a and 122 b which are dimensioned to receivepivot pin 59. When assembled, pivot pin 59 also passes through apertures53 a, 53 b of pivot block 50 along the “Y” axis. Rotation of the pivotblock 50 about the “Y” axis correspondingly rotates tool assembly 100about the “Y” axis. Rotation of pivot block 50 about pin 57 along “Z”axis rotates tool assembly 100 about the “Z” axis.

As best shown in FIG. 6B, bottom surface 128 of channel assembly 120also includes an elongated longitudinal slot 126 which includes andcommunicates at its proximal end with a cut out or notch 129. Notch 129is dimensioned to allow bottom flange 152 of dynamic clamping member 150to pass therethrough. The narrower portion of slot 126 is dimensioned toslidingly receive and allow upward support or extension 151 to passtherethrough. More particularly and as also shown in FIGS. 7A and 7B,bottom flange 152 of dynamic clamping member 150 is passed throughopening or channel 164 through cut out or notch 167 in the base of sled160, and through notch 129 in bottom wall 128 of channel assembly 120.When bottom flange 152 of dynamic clamping member 150 is extended belowthe surface of bottom wall 128 of channel 120, dynamic clamping member150 is moved distally so that bottom flange 152 slidingly engages theunderside of bottom wall 128 adjacent slot 126 and upward extension 151engages in channel 164. As can be appreciated, this slidingly locksbottom flange 152 of the dynamic damping member 150 and sled 160 withinthe channel assembly 120.

Bottom flange 152 of dynamic damping member 150 in cooperation with thepin 159 and slot 112 arrangement of dynamic damping member 150 and anvilassembly 110, slidingly secure the dynamic clamping member 150 withinopposing slots 126 and 112 and prevents unintentional displacement ofanvil assembly 110 relative to staple cartridge assembly 200 (eithervertically (“Z” axis”) or transversely (“Y” axis)) during the clamping,fastening and severing procedures. As mentioned above, the heavy gaugematerial of the anvil assembly 110 also reduces unintentionaldisplacement of the dynamic damping member 150 during distal translationthereof. Thus, in addition to severing tissue 400, dynamic dampingmember 150 of the present disclosure also acts to oppose the forcesassociated with compression of tissue, deformation of the surgicalfasteners 500 and severing of tissue 400.

As mentioned above, bottom surface 128 of channel assembly 120 acts as acarrier to define elongated support channel 125 for receiving the staplecartridge assembly 200. With respect to the staple cartridge assembly200, corresponding tabs 235 a, 235 b, 235 c, 235 d formed along staplecartridge assembly 200 and elongated support channel 125 function toretain staple cartridge assembly 200 within support channel 125 (SeeFIG. 11C). Staple cartridge assembly 200 also includes offset retentionslots 225 for receiving a plurality of fasteners 500 and staple pushers228 therein. A series of spaced-apart longitudinal slots 230 extendthrough staple cartridge assembly 200 to accommodate a pair of upwardlyextending, bifurcated cam wedges 161 a, 161 b of sled 160. As best shownin FIG. 11A, a centrally-located, longitudinal slot 282 extendssubstantially along the length of staple cartridge assembly 200 tofacilitate passage of upward extension 151 of dynamic damping member 150therethrough. When deformed using the embodiment shown, the surgicalfasteners 500 form two sets of three staple rows 232 a and 232 b, oneset to each side of slot 282.

When tool member 100 is assembled, sled 160 is slidingly positionedbetween the staple cartridge assembly 200 and the channel assembly 120(See FIG. 3). Sled 160 and the inner-working components of staplecartridge assembly 200 detailed above operatively cooperate to deformstaples 500. More particularly, sled 160 includes upwardly extending,bifurcated cam wedges 161 a and 161 b which engage and cooperate with aseries of staple pushers 228 to drive staples 350 through slots 225 fromcartridge assembly 200 and deform against staple forming pockets 11 ofanvil assembly 100.

During operation of the surgical stapler 10, sled 160 translatespreferably distally through longitudinal slots 230 of staple cartridgeassembly 200 to advance cam wedges 161 a and 161 b into sequentialcontact with pushers 228, to cam and cause pushers 228 to translatevertically within retention slots 225 and urge fasteners 500 fromretention slots 225 against fastener forming pockets 111 in bottomfacing surface 114 b of anvil assembly 110 (See FIG. 4). One such typeof staple forming pocket or cavity 111 is shown and described incommonly owned U.S. Pat. No. 6,330,965 the entire contents of which arehereby incorporated by reference herein.

As mentioned above, dynamic clamping member 150 is mounted on andpreferably rides atop, on or in sled 160 (FIGS. 7A and 7B). In theembodiment shown, when assembled, the lower portion of upward extension151 of dynamic clamping member 150 is generally positioned in slot 164defined in sled 160 axially between the proximally facing edge 166 a ofspacer 166 and the distally facing edge 162 b and upwardly extendingproximal edge 162 a of a rear flange 162.

Dynamic clamping member 150 is secured to sled 160 through a slot 167that extends through the base of sled 160. More particularly, the baseof upward extension 151 of dynamic clamping member 150 is securelydisposed with the second slot 167 which extends through the bottom ofsled 160 and is defined by proximally facing or trailing edge 166 b of aspacer 166 and the distal edge 162 b of flange 162. Specifically, theleading edge 153 a (FIG. 10) of upper extension 151 abuts against thetrailing edge of spacer 166 b and the trailing edge 153 b (FIG. 10) ofupper extension 151 abuts against distal edge 162 b of flange 162 toaxially secure dynamic clamping member 150 to and axially in sled 160.

Leading edge 166 a of the spacer 166 rides within and along slot 282 ofstaple cartridge assembly 200 to positively guide the sled 160 along anideal stapling and cutting path preferably centrally and axially throughthe tissue 400. Thus, upon distal movement of sled 160 to eject surgicalfasteners 500, dynamic clamping member 150, securely disposed withinsled 160, travels along slot 282 of staple cartridge assembly 200 andsequentially severs tissue 400 between the two rows 232 a and 232 b offormed fasteners 500 (See FIG. 11A). As explained in more detail belowwith respect to FIGS. 12 and 13, the distal end of sled 160 may includesapertures 169 a and 169 b to receive a suitable elongated flexiblemember, e.g., a cable 900, which upon movement thereof advances sled 160to form surgical fasteners 500 and sever tissue 400.

As best shown in FIG. 10, dynamic clamping member 150 includes an upperportion 157 having a transverse aperture 154 with a pin 159 mountable ormounted therein, a central support or upward extension 151 andsubstantially T-shaped bottom flange 152 which, as described above,mutually cooperate to slidingly retain dynamic clamping member 150 alongan ideal cutting path during longitudinal, distal movement of sled 160.The leading cutting edge 155, here, knife blade 155 a, is dimensioned toride within slot 282 of staple cartridge assembly 200 and separatetissue 400 once stapled. It is envisioned that leading edge 155 of thedynamic clamping member 150 may be serrated, beveled or notched tofacilitate tissue cutting. More particularly, it is contemplated thatthe combination of the enhanced closure force as a result of the heavygauge material of the anvil assembly 110 together with the abovedescribed uniquely designed or positioned dynamic clamping member 150(or dynamic clamping member 150″ of FIG. 14) permits accurate cutting oftissue 400 when leading edge 155 is advanced through tissue 400. It isalso understood that the upper camming member need not be a pin but canbe any integral or removable suitable outwardly protruding camsurface(s). The same applies to bottom flange 152 which can be anysuitable camming surface, including a pin or a removable pin, a buttonto facilitate mounting of the dynamic clamping member into the sled 160or channel assembly 120.

It is also envisioned that the strength of the over and under cammingconfiguration of dynamic clamping member 150 in combination with theincreased strength of anvil assembly 110 (i.e., made from a heavy gaugesurgical stainless steel) also prevents dynamic damping member 150 fromcutting vertically offline or buckling and eliminates the need tocantilever dynamic clamping member 150 as it moves through tissue 400.In other words, by preferably utilizing a heavy gauge material for theanvil assembly 110 (and possibly the channel assembly 120) and utilizingsubstantially aligned upper and lower slidingly engaging surfaces of thedynamic clamping member 150 (here, pin 159 and bottom flange 152) toride between the anvil assembly 110 and the channel assembly 120 insubstantial vertical registration, the normal forces associated withstapling and cutting tissue 400 are sufficiently opposed thusmaintaining a consistent maximum and substantially uniform gap in thestapling and cutting area between the opposing tissue contactingsurfaces (i.e., staple cartridge surface 231 and bottom anvil surface114 b) during the stapling and cutting processes. Moreover, theprovision of the heavy gauge material for the anvil assembly 110 and thearrangement of the pin 159 and bottom flange 152 also operate to furtherproximate or further clamp the tissue at a point distal to the dynamicdamping member 150 which forces fluid from the tissue 400 to furtherenhance the stapling and cutting processes. It is envisioned thatalternative upper and lower sliding camming surfaces may be employed toaccomplish a similar purpose, e.g., plates, rails, ball bearing etc.

From the foregoing and with reference to the various figure drawings,those skilled in the art will appreciate that certain modifications canalso be made to the present disclosure without departing from the scopeof the present disclosure. For example, the above-described toolassembly 100 may be part of or incorporated into a disposable loadingunit (DLU) such as disclosed in U.S. Pat. No. 6,330,965 or attacheddirectly to the distal end of any known surgical stapling device. Ahandle assembly for actuating the approximation member(s) can beselected from a variety of actuating mechanisms including toggles,rotatable and slideable knobs, pivotable levers or triggers, and anycombination thereof. The use of the above-described tool assembly 100 aspart of a robotic system is also envisioned.

It is also envisioned that many different actuators may be employed toadvance the sled 160 through the tissue 400. For example, it isenvisioned that the tool assembly 100 (or one of the sub-assembliesassociated therewith, i.e., channel assembly 120 or staple cartridgeassembly 200 or anvil assembly 110) may include one or more pulleys toadvance the sled 160 through the tissue 400 to staple and cut the same.

For example, as shown in FIG. 12A, a pair of cables, ropes, threads orbands or belts 700 a, 700 b may be fed distally through cartridgeassembly 200 or channel assembly 120 through or around respective pins,capstans, or pulleys 600 a, 600 b, and pass proximally toward and attachto sled 160. Alternatively and as shown in FIG. 128, a single belt canreplace belts 700 a and 700 b and can be passed through apertures 169 aand 169 b at the distal end of sled 160, or passed into a gap 163 andaround behind a pin 610 which is mounted through apertures 169 a and 169b.

One or more pins 610 may be disposed within sled 160 such that aproximal force “F” on the corresponding bands 700 a and 700 b advancesthe sled 160 distally to eject and form staples 500 against anvilassembly 110 and cut tissue 400. It is envisioned that the band or beltsmay be made from a high strength material sold under the trademarkKevlar® or other man-made fibers or materials available for generalizeduse in the industrial arts and suitable for this intended surgical use.As can be appreciated, utilizing a dual pin or pulley system asschematically shown in FIG. 12 maintains the balance of theproximally-actuated forces “F” on either side of staple cartridgeassembly 200 as sled 160 moves through tissue 400. As also can beappreciated, this assures uniform and consistent stapling and cutting oftissue 400 by dynamic clamping member 150.

FIG. 13 shows one possible suitable actuating system to actuatepre-clamping collar 140 to force anvil assembly 110 to close relative tostaple cartridge assembly 200. More particularly, a cable 900 may beutilized to move pre-clamping collar 140 distally onto and over camsurface 115 to close the anvil 110 relative to the staple cartridgeassembly 200 and compress the tissue 400. Preferably, cable 900 attachesto the pre-clamping collar 140 at or near point 149 and is fed through apassageway in anvil assembly 110 (or under a proximal portion of anvilassembly 110) and fed proximally through shaft 20. Actuating of cable900 in the direction “C” forces pre-damping collar 140 distally againstcam surface 115 to close anvil assembly 110 relative to staple cartridgeassembly 200. A return mechanism, e.g., a spring, cable system or thelike (not shown), may be employed to return pre-clamping collar 140 to apre-clamping orientation which re-opens anvil assembly 110.

FIG. 14 shows an alternate embodiment of a dynamic damping collar 150″which includes an upper portion 157″ having a transverse aperture 154within which pin 159 is mountable or mounted therein, upward extension151 and substantially T-shaped bottom flange 152″ which, as similarlydescribed above with respect to FIG. 10, mutually cooperate to slidinglyretain dynamic damping member 150″ along an ideal cutting path duringlongitudinal, distal movement of sled 160. The leading cutting edge 155″of knife blade 155 a″ is dimensioned to ride within slot 282 of staplecartridge assembly 200 and separate tissue 400 once stapled.

It is envisioned that the combination of the enhanced closure force as aresult of the heavy gauge material of the anvil assembly 110 togetherwith uniquely designed dynamic clamping member 150″ permits accuratecutting of tissue 400 when leading edge 155″ is advanced through tissue400. It is also contemplated that the strength of the over and undercamming configuration of dynamic clamping member 150″ in combinationwith the increased strength of anvil assembly 110 (i.e., made from aheavy gauge surgical stainless steel) also prevents dynamic dampingmember 150″ from cutting vertically offline or buckling and eliminatesthe need to cantilever dynamic clamping member 150″ as it moves throughtissue 400. In other words, by preferably utilizing a heavy gaugematerial for the anvil assembly 110 substantially aligning upper andlower slidingly engaging surfaces in vertical registration, dynamicclamping member 150″ rides between the anvil assembly 110 and thechannel assembly 120 in substantial vertical registration and the forcesassociated with stapling and cutting tissue 400 are sufficiently opposedthus maintaining a consistent maximum and substantially uniform gap inthe stapling and cutting area between the opposing tissue contactingsurfaces 231 and 114 b during the stapling and cutting processes.

The dynamic clamping member 150, 150″ of this disclosure is animprovement over known clamping members. Since the upper and lowercamming surfaces are substantially opposed, i.e., substantiallyvertically aligned, the forces to which it is subjected during itsoperation are substantially only tensile forces. Consequently, thedesign of the dynamic clamping member 150 renders it significantlystrong and significantly resistant to buckling. Accordingly, the cuttingedge 155 is unlikely to buckle. Further, since the cutting edge 155 forcutting tissue is also substantially aligned with the upper and lowercamming surfaces 159 and 152, the dosing force of the dynamic dampingmember 150 is imparted closer to and preferably more aligned with thecutting edge. This enhances the cutting action of the cutting edge.

The preferred use of a damping collar 140 to pre-damp, i.e., initiallyapproximate the anvil assembly 110 and cartridge assembly 200, incombination with the use of a dynamic clamping member 150 tosubsequently clamp, preferably further damp, i.e., further proximate,the anvil 110 and cartridge 200 assemblies, provides several advantages.It enhances tissue stabilization and compression. During pre-clampingand approximation, clamping collar 140 squeezes, i.e., pre-squeezestissue, between and distally along the respective tissue contracting orfacing surfaces of the anvil assembly 110 and cartridge assembly 120.During subsequent, preferably further clamping and proximation with thedynamic damping member 150, there is believed to be less fluid and fluidflow in the tissue in the area of further damping. This enhancesobtaining a uniform tissue gap and better staple formation along thetool assembly 100. With less fluid flow in the area of and duringstapling, staple legs more accurately hit their staple pockets 111 inthe anvil 110 forming surface. The advantages pre-damping and subsequentclamping are further enhanced by use of stronger heavier gauge anvilassembly 110, for example because there is less of a tendency for distalend of anvil assembly 110 to bow outwardly away from cartridge assembly200. Also, the squeezing effect on the tissue during pre-clamping andclamping is more pronounced, increasingly so from the mid to distal endof the anvil assembly 110. Consequently, tissue fluid is forced furtherdistally out to and past the distal end of the anvil assembly 110 andtool assembly 100. This reduces fluid flow in the area of and duringstapling with the dynamic damping member 150. In addition to thebenefits explained above, this reduces the need to cantilever thecamming force out ahead of the clamping member 150, and allows the uppercamming surface here, pin 159, to be effectively disposed insubstantially vertical alignment meaning at least some portion of theupper and lower camming surfaces 159, 152 are vertically aligned. Thus,the most preferred arrangement and procedure is to have a clampingcollar 140 for pre-clamping, a dynamic clamping member 150 for furtherclamping, and each being effected on a strong, or, preferably, verystrong anvil assembly 110.

The present disclosure also relates to a method of stapling tissue andincludes the steps of providing a stapler having a tool assembly at adistal end thereof, the tool assembly including a channel assembly forsupporting a staple cartridge which carries a plurality of staples andan anvil dimensioned having, e.g., shaped pockets to deform theplurality of staples ejected from the staple cartridge thereagainst. Thetool assembly also includes a sled which is movable from a firstposition to a subsequent position to force the plurality of staples fromthe staple cartridge through tissue and against the anvil, and a dynamicclamping member which moves with the sled. The dynamic damping memberincludes a first mechanical interface which slidingly engages the anviland a second mechanical interface which slidingly engages the channelassembly. The first and second mechanical interfaces of the dynamicclamping member are in substantial vertical registration relative to oneanother to oppose the expansive forces associated with clamping,stapling, and if a knife is engaged on the dynamic clamping member,cutting tissue.

The method according to the present invention also includes the stepsof: approximating and grasping tissue between the opposing surfaces ofthe anvil and the staple cartridge; clamping the anvil and staplecartridge in position about the tissue; and firing the stapler toadvance the sled and the dynamic clamping member distally to eject thestaples from the staple cartridge to deform against the anvil to fastenthe tissue and to subsequently cut the tissue along a predeterminedcutting path. The firing step can employ the substantially over andunder dynamic clamping member to further proximate the opposing surfacesof the anvil assembly and the staple cartridge at progressively movingpoints which are distal to the knife during translation of the dynamicdamping member.

Although the subject surgical stapler and various assemblies associatedtherewith have been described with respect to preferred embodiments, itwill be readily apparent to those having ordinary skill in the art towhich it appertains that changes and modifications may be made theretowithout departing from the spirit or scope of the subject devices. Whileseveral embodiments of the disclosure have been shown in the drawingsand described herein, it is not intended that the disclosure be limitedthereto, as it is intended that the disclosure be as broad in scope asthe art will allow and that the specification be read likewise.Therefore, the above description should not be construed as limiting,but merely as exemplifications of preferred embodiments. Those skilledin the art will envision other modifications within the scope and spiritof the claims appended hereto.

What is claimed is:
 1. A tool assembly comprising: an anvil, a supportchannel, and a staple cartridge assembly selectively mounted in thesupport channel to permit replacement of the staple cartridge assemblyduring a surgical procedure, the staple cartridge assembly including aplurality of staples aligned in a plurality of linear rows and a sledfor effecting ejection of the plurality of staples from the staplecartridge assembly, the staple cartridge assembly and anvil beingmovable in relation to one another between an open position and anapproximated position, the staple cartridge assembly and the anvildefining a tissue gap in the approximated position; a dynamic clampingmember movably positioned in relation to the anvil and the staplecartridge assembly, the dynamic clamping member being movable from afirst position to a second position to define a maximum tissue gapbetween the anvil and the staple cartridge assembly adjacent the dynamicclamping member during ejection of the plurality of staples from thestaple cartridge assembly; and a flexible actuator operativelyassociated with the dynamic clamping member to effect movement of thedynamic clamping member from the first position of the dynamic clampingmember to the second position of the dynamic clamping member.
 2. A toolassembly according to claim 1, wherein the sled is movable with thedynamic clamping member through the staple cartridge assembly from afirst position to a subsequent position to operatively eject theplurality of staples from the staple cartridge assembly through tissueand against the anvil to staple tissue disposed between the anvil andthe staple cartridge assembly.
 3. A tool assembly according to claim 1,wherein the dynamic clamping member includes a first mechanicalinterface which slidingly engages the anvil and a second mechanicalinterface which slidably engages the staple cartridge assembly, thefirst and second mechanical interfaces of the dynamic clamping memberbeing in substantial vertical registration relative to one another tooppose expansive forces associated with clamping and stapling tissue andto define the maximum tissue gap between tissue contacting surfaces ofthe anvil and the cartridge assembly during stapling.
 4. A tool assemblyaccording to claim 1, wherein the staple cartridge assembly is pivotallysecured to an intermediate pivot member and the anvil is pivotallysupported on the staple cartridge assembly.
 5. A tool assembly accordingto claim 1, wherein the dynamic clamping member translates axiallythrough the tool assembly.
 6. A tool assembly according to claim 1,wherein the actuator is selected from the group consisting of cables,ropes, threads, bands and belts.
 7. A tool assembly according to claim1, wherein the actuator is operably connected to the sled and the sledis operably connected to the dynamic clamping member.
 8. A surgicalstapler according to claim 7, wherein the tool assembly is rotatableabout two axes.
 9. A surgical stapler according to claim 7, wherein theflexible actuator extends through the staple cartridge assembly andaround a capstan.
 10. A surgical stapler having the tool assemblyaccording to claim 1, further comprising a shaft connector portion. 11.A surgical stapler according to claim 10, wherein the shaft connectorportion is removably associated with a robotic system.
 12. A surgicalstapler according to claim 1, further including a knife for incisingtissue disposed between the anvil and the staple cartridge assembly. 13.A tool assembly comprising: an anvil, a support channel, and a staplecartridge assembly selectively mounted in the support channel to permitreplacement of the staple cartridge assembly during a surgicalprocedure, the staple cartridge assembly including a plurality ofstaples aligned in a plurality of linear rows and a sled for effectingejection of the plurality of staples from the staple cartridge assembly,the staple cartridge assembly and anvil being movable in relation to oneanother between an open position and an approximated position, thestaple cartridge assembly and the anvil defining a tissue gap in theapproximated position a dynamic clamping member movably positioned inrelation to the anvil and the staple cartridge assembly, the dynamicclamping member being movable from a first position to a secondposition; and a flexible actuator operatively associated with thedynamic clamping member to effect movement of the dynamic clampingmember from the first position of the dynamic clamping member to thesecond position of the dynamic clamping member.
 14. A tool assemblyaccording to claim 13, wherein the sled is movable with the dynamicclamping member through the staple cartridge assembly from a firstposition to a subsequent position to operatively eject the plurality ofstaples from the staple cartridge assembly through tissue and againstthe anvil to staple tissue disposed between the anvil and the staplecartridge assembly.
 15. A tool assembly according to claim 14, whereinthe actuator is operably connected to the sled and the sled is operablyconnected to the dynamic clamping member.
 16. A tool assembly accordingto claim 13, wherein the dynamic clamping member includes a firstmechanical interface which slidingly engages the anvil and a secondmechanical interface which slidably engages the staple cartridgeassembly, the first and second mechanical interfaces of the dynamicclamping member being in substantial vertical registration relative toone another to oppose expansive forces associated with clamping andstapling tissue and to define the maximum tissue gap between tissuecontacting surfaces of the anvil and the staple cartridge assemblyduring stapling.
 17. A tool assembly according to claim 13, wherein thestaple cartridge assembly is pivotally secured to an intermediate pivotmember and the anvil is pivotally supported on the staple cartridgeassembly.
 18. A tool assembly according to claim 13, wherein the dynamicclamping member translates axially through the tool assembly.
 19. A toolassembly according to claim 13, wherein the actuator is selected fromthe group consisting of cables, ropes, threads, bands and belts.
 20. Asurgical stapler having the tool assembly according to claim 13, furthercomprising a shaft connector portion.
 21. A surgical stapler accordingto claim 20, wherein the shaft connector portion is removably associatedwith a robotic system.
 22. A surgical stapler according to claim 20,wherein the tool assembly is rotatable about two axes.
 23. A surgicalstapler according to claim 13, further including a knife for incisingtissue disposed between the anvil and the staple cartridge assembly.